The present disclosure relates generally to a formulation in the form of an emulsion which includes a combination gum blend and a salt tolerant emulsifier, and items using same. The combination provides physical stability to an emulsion containing both zinc salts and silicone oil. The formulation of the present disclosure is useful for rash prevention and may be applied to the skin with a wipe wetted therewith or by other various means.
Wet wipes have been used for years for convenient skin cleansing between diaper changes. Much headway has been made in creating formulations for wet wipes. Such formulations are in the form of emulsions which provide a vehicle for the application of active ingredients to the skin. Such ingredients may be used to treat and/or prevent diaper rash.
Diaper rash is a form of contact dermatitis which afflicts infants or incontinent persons whose wet and/or soiled absorbent garments are not promptly changed. Because of the practical impossibility of attending promptly to all of a person's needs, even those receiving a high level of care sometimes suffer from diaper rash. It has recently come to be understood that the initial stages of some types of diaper rash are the result of skin irritation caused by contact with digestive enzymes present in feces, particularly trypsin, chymotrypsin and elastase. These enzymes are proteolytic enzymes produced in the gastrointestinal tract to digest food. Similar conditions conducive to skin irritation by proteolytic enzymes present in feces are found in patients having colostomies. Such patients would also benefit from improved treatments to prevent skin irritation due to fecal enzymes.
Silicone oil is a commonly used active ingredient that acts as a skin barrier to prevent diaper rash. While there are several methods to achieve stable emulsions with silicone oil at concentrations compliant with its use as an over-the-counter drug, there are several disadvantages associated with these methods. First, the concentration of emulsifier required to successfully stabilize an emulsion containing the silicone oil, e.g. dimethicone, can be so great that it is cost prohibitive. Second, obtaining a low-viscosity, sprayable solution can be difficult due to the high probability that silicone oil droplets will coalesce, particularly at the elevated temperatures to which the solution may be exposed. Third, without appropriately modifying the rheology of the water phase, emulsions with a low viscosity and low solids content tend to undergo phase separation, particularly following a freeze-thaw cycle. This results in a non-uniform product that would not be efficacious.
Sometimes a skin barrier alone is not enough to prevent diaper rash, especially when fecal matter is present. Therefore, it is also desirable to inhibit skin irritants such as proteolytic enzymes. One way to inhibit such enzymes is to apply a water-soluble zinc salt to the skin. Zinc has long been known to sooth irritated skin/prevent skin irritation. However, zinc salts are not very compatible with silicone oils because when combined together in an emulsion, the emulsion can phase separate due to the increased ionic strength.
Accordingly, there is a need for an emulsion that contains silicone oil as an active ingredient and does not phase separate even in the presence of zinc salts. There is a further need to stabilize an emulsion containing silicone oil in a manner that is cost effective. It would be further advantageous if the emulsion would be suitable for spraying onto a substrate during the manufacture of a wet wipe. In addition, there is a need to preserve the emulsion without causing phase separation, especially if the emulsion is to be applied to a substrate.